GCN Circular 30089
Subject
GRB 210527A: Swift/UVOT Observations
Date
2021-05-28T12:22:26Z (3 years ago)
From
Mike Siegel at PSU/Swift MOC <mhs18@psu.edu>
M. H. Siegel (PSU) and S. L. Laha (GSFC/UMBC/CRESST)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 210527A
3164 s after the BAT trigger (Laha et al., GCN Circ. 30081).
No optical afterglow consistent with the XRT position
(Evans et al., GCN Circ. 30083) is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first
finding chart (FC) exposure and subsequent exposures are:
Filter T_start(s) T_stop(s) Exp(s) Mag
white_FC 3164 3313 147 >20.2
white 3164 3932 344 >21.2
v 4143 4343 197 >19.4
b 3528 3727 197 >20.4
u 3322 4895 331 >20.4
w1 4553 4753 197 >20.2
m2 4348 4548 197 >20.0
w2 3938 4138 197 >20.5
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.023 in the direction of the burst
(Schlegel et al. 1998).